Additive manufacturing method and assembly

ABSTRACT

Methods and assemblies for additive manufacturing portions of components with enhanced strength are provided. The assemblies comprise a first deposition head and an apparatus for causing one or more reinforcement fibers to extend more than two layers within previously-deposited layers of build material. The first deposition head is configured to deposit a plurality of layers of a filament comprising a reinforcement fiber and thermoplastic material. The apparatus may comprise a needle point configured to be inserted into the plurality of layers to displace the reinforcement fiber so that it extends two or more of the plurality of layers. The apparatus may additionally or alternatively comprise a second deposition head having a needle tip configured to be inserted into the plurality of layers to inject a length of a second filament comprising thermoplastic material and a reinforcement fiber so that the reinforcement fiber of the second filament extends two or more layers of the plurality of layers of the first filament.

RELATED APPLICATIONS

The present invention is a divisional application and claims priority ofco-pending application titled “ADDITIVE MANUFACTURING METHOD ANDASSEMBLY,” Ser. No. 16/705,363, filed Dec. 6, 2019, which isincorporated by reference herein in its entirety.

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with Government support under Contract No.:DE-NA-0002839 awarded by the United States Department of Energy/NationalNuclear Security Administration. The Government has certain rights inthe invention.

BACKGROUND

Carbon fibers are often added to matrix materials, such as nylon orepoxy, to enhance the strength of the materials. Carbon fibers aretypically thin, exceptionally strong in the axial direction, and addlittle weight to the matrix materials. Carbon fibers may be encapsulatedby resin and shaped to form a part. Carbon fibers may also be depositedbetween layers of printed build material to strengthen partsmanufactured using three-dimensional printers. The strands of carbonfiber increase the lateral strength of the part along the direction thebuild material was deposited. However, parts formed in this manner donot experience improved axial strength in directions that are notparallel to the direction the thermoplastic material was deposited.

The background discussion is intended to provide information related tothe present invention which is not necessarily prior art.

SUMMARY

The present invention solves the above-described problems and otherproblems by providing a distinct advance in the art of carbon fibersused in additive manufacturing. More particularly, the present inventionprovides methods of and assemblies for additive manufacturing thatenable placement of reinforcement fibers at multiple angles to enhancepart strength in multiple axial directions.

An embodiment of the invention includes a method of additivemanufacturing a portion of a component. The method comprises depositingvia a fused-deposition manufacturing (FDM) deposition head a pluralityof layers of a filament to form the portion of the component. Thefilament comprises thermoplastic material and a reinforcement fiber. Themethod further comprises inserting an end of an apparatus into theplurality of layers to displace the reinforcement fiber positionedwithin one of the plurality of layers so that the reinforcement fiberhas a displaced portion that extends two or more layers of the pluralityof layers. By displacing the reinforcement fiber in this way, thestrength of the additive manufactured portion is enhanced along multipleaxial directions.

A method of additive manufacturing a portion of a component according toanother embodiment of the present invention comprises depositing via afirst FDM deposition head a plurality of layers of a first filament toform the portion of the component. The first filament comprisesthermoplastic material and a reinforcement fiber. The method furthercomprises inserting a needle tip of a second FDM deposition head intothe plurality of layers; and depositing via the needle tip of the secondFDM deposition head a length of a second filament comprisingthermoplastic material and a reinforcement fiber so that the lengthextends two or more layers of the plurality of layers.

Another embodiment of the invention is an additive manufacturingassembly comprising a first FDM deposition head and a needle point. Thefirst FDM deposition head is configured to deposit a plurality of layersof a filament comprising a reinforcement fiber and thermoplasticmaterial. The needle point is configured to be inserted into theplurality of layers to displace the reinforcement fiber so that itextends two or more layers of the plurality of layers.

Another embodiment of the invention is an additive manufacturingassembly comprising a first FDM deposition head and a second FDMdeposition head. The first FDM deposition head is configured to deposita plurality of layers of a first filament. The first filament comprisesa reinforcement fiber and thermoplastic material.

The second FDM deposition head has a needle tip configured to beinserted into the plurality of layers to inject a length of a secondfilament. The second filament comprises thermoplastic material and areinforcement fiber. The length of the second filament is injected intothe plurality of layers so that the reinforcement fiber of the secondfilament extends two or more layers of the plurality of layers of thefirst filament.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the present invention will be apparent from thefollowing detailed description of the embodiments and the accompanyingdrawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of the present invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a perspective view of an exemplary additive manufacturingsystem which may implement aspects of the present invention;

FIG. 2 is a perspective view of an assembly that may be used in thesystem of FIG. 1 and that is constructed in accordance with anembodiment of the present invention;

FIG. 3 is a perspective view of an assembly that may be used in thesystem of FIG. 1 and that is constructed in accordance with anotherembodiment of the present invention;

FIG. 4 is a flowchart illustrating a method of additive manufacturing aportion of a component according to an embodiment of the presentinvention; and

FIG. 5 is a flowchart illustrating a method of additive manufacturing aportion of a component according to another embodiment of the presentinvention.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following detailed description of the invention references theaccompanying drawings that illustrate specific embodiments in which theinvention can be practiced. The embodiments are intended to describeaspects of the invention in sufficient detail to enable those skilled inthe art to practice the invention. Other embodiments can be utilized andchanges can be made without departing from the scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense. The scope of the present invention is definedonly by the appended claims, along with the full scope of equivalents towhich such claims are entitled.

In this description, references to “one embodiment”, “an embodiment”, or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment”, “an embodiment”, or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the present technology can include a variety of combinationsand/or integrations of the embodiments described herein.

Turning to FIG. 1, an exemplary additive manufacturing system 10 whichmay implement aspects of the present invention is shown. The additivemanufacturing system 10 is configured to manufacture at least a portionof a three-dimensional (3D) component 12 such as a high-strength,fiber-reinforced polymer structural part. An embodiment of the system 10broadly comprises a housing 14 having an inner chamber 16, a buildplatform 18 positioned in the chamber 16, and an additive manufacturingassembly 20 positioned above the build platform 18. The system 10 may bea 3D printer, a welding machine, a VAT photopolymerization system, apowder bed fusion system, a binder jetting system, a material jettingsystem, or the like.

The housing 14 protects the components of the system 10 duringmanufacturing and maintains a suitable environment about the buildplatform 18. The housing 14 encloses the component 12, the buildplatform 18, and the assembly 20 in its chamber 16. The build platform18 supports the component 12 as the component 12 is being manufactured.The platform 18 may be secured beneath the assembly 20 and/or bemoveable relative to the assembly 20.

Turning to FIG. 2, an embodiment of the additive manufacturing assembly20 is depicted. The assembly 20 is moveable above the build platform 18and is operable to deposit build material onto the platform 18 to format least a portion of the component 12. The assembly 20 comprises afused-deposition manufacturing (FDM) deposition head 22 and a needleapparatus 24.

The deposition head 22 deposits a plurality of layers 26 of filament 28onto the platform 18 and/or onto a layer of filament that was previouslydeposited. The deposition head 22 may comprise an extruder 30, a heaterblock 32, and a nozzle 34. The extruder 30 forces the filament 28through the deposition head 22. The heater block 32 heats a portion ofthe filament 28 as it is forced through the deposition head 22 to thenozzle 34. The heated portion of the filament 28 is then forced out thenozzle 34 to a desired location, such as the build platform 18 and/oronto a layer of filament 28 that was previously deposited.

The filament 28 is used to form the portion of the component 12 and maycomprise a matrix material 36 and one or more reinforcement fibers 38.The matrix material 36 may comprise thermoplastic material. Thereinforcement fibers 38 may comprise carbon fiber, glass fiber, basaltfiber, ceramic fiber, metal fiber, aramid fiber, polyester fibers,natural fibers, metallized versions of the aforementioned fibers, or thelike. The reinforcement fibers 38 may be at least partially coaxial withthe filament 28 so that fibers 38 in the plurality of layers 26 areparallel with the layers 26. While FIG. 2 depicts filament 28 having aplurality of fibers 38 in each of the layers 26, the filament 28 mayhave only one fiber 38 per layer 26.

The needle apparatus 24 is operable to cause one or more of the fibers38 in the plurality of layers 26 to extend one or more layers 26, and inpreferred embodiments, at least three of the layers 26. The needleapparatus 24 may comprise a heated needle 40 and a needle driver 42. Theneedle 40 has a barb point 44 small enough to be inserted into thelayers 26 to physically displace one or more of the fibers 38 therein sothat the displaced fibers 46 extend into at least three of the layers26. The driver 42 is configured to cause the needle 40 to reciprocatevertically into the layers 26 and out of the layers 26 as the needleapparatus 24 moves above the platform 18. The driver 42 may be operatedby mechanical means, such as gears and an electric motor or the like, asolenoid-actuator, a pneumatic actuator, or the like. By causing thefibers 38 to extend beyond just two of the layers 26, the vertical axialstrength of the portion of the component 12 is greatly enhanced andrequires fewer passes of the needle apparatus 24 over the layers 26.

In use, the deposition head 22 deposits a plurality of layers 26 ontothe build platform 18, onto a previously-deposited layer, and/or onto apre-existing part. As the deposition head 22 moves above the layers 26,the needle apparatus 24 is inserted into the plurality of layers 26 topush a portion of one of the fibers 38 of the filament 28 to form thedisplaced fiber. The heated needle 44 of the needle apparatus 24displaces the displaced fiber 46 so that the displaced fiber 46 has aportion that extends from its original layer 48 to at least two layers50, 52 below the original layer 48. The needle 44 may be driven by theneedle drive 42 so that it is inserted substantially orthogonally to thelayers 26. However, the needle 44 may be inserted at different anglesrelative to the layers 26 without departing from the scope of thepresent invention.

An additive manufacturing assembly 20A constructed in accordance withanother embodiment of the invention is depicted in FIG. 3. The assembly20A may comprise substantially similar components as assembly 20; thus,the components of assembly 20A that correspond to similar components ofassembly 20 have an ‘A’ appended to their reference numerals.

The assembly 20A includes all the features of assembly 20 except thatthe first filament 28A is preferably a continuous strand of fiber andinstead of a needle apparatus 24, assembly 20A comprises a second FDMdeposition head 54A.

The second deposition head 54A is operable to inject lengths 46A of asecond filament 56A into the plurality of layers 26A. The seconddeposition head 54A may be configured to inject the lengths 46A of thesecond filament 56A so that the lengths 46A extend at least three of thelayers 26A. The second deposition head 54A may comprise an extruder (notshown), a needle driver 42A, a heater block 58A, a nozzle 60A, a heatedneedle 62A, and a cutting device 64A. The extruder forces the filament56A through the second deposition head 54A. The needle driver 42A isoperable to cause the needle 62A to reciprocate vertically into thelayers 26A and out of the layers 26A as the second deposition head 54Amoves above the platform 18A. The heater block 58A heats a portion ofthe filament 56A as it is forced through the second deposition head 54A.The heated portion of the filament 56A is then forced out the nozzle 60Ato the heated needle 62A. The needle 62A is a syringe-like needle havinga bore for injecting the filament 56A into the layers 26A and/ordisplacing fiber 38A of the layers 48A, 50A, 52A. For example, theneedle 62A may be configured to displace the fiber 38A in the layer 48Aso that a portion of the fiber 38A extends between two or more of thelayers 48A, 50A, 52A, similar to barb point 44 of needle 40. The cuttingdevice 64A is configured to cut the length 46A of the filament 56A offfrom the rest of the filament 56A below the needle 62A after the length46A of the filament 56A has been injected into the layers 26A.

The filament 56A is used to form the lengths 46A that are injected intothe layers 26A and may comprise a matrix material 66A and one or morereinforcement fiber 68A. The matrix material 66A may comprisethermoplastic material. The reinforcement fiber 68A may comprise carbonfiber, glass fiber, basalt fiber, ceramic fiber, metal fiber, aramidfiber, polyester fibers, natural fibers, metallized versions of theaforementioned fibers, or the like. The reinforcement fiber 68A may beat least partially coaxial with the filament 56A so that the fiber 68Ais parallel with the needle 62A as it is forced therethrough. While FIG.3 depicts filament 56A having one fiber 68A, the filament 56A may haveany number of fibers 68A without departing from the scope of the presentinvention.

In use, the deposition head 22A deposits a plurality of layers 26A ontothe build platform 18, onto a previously-deposited layer, and/or apre-existing part. As the deposition head 22A moves above the layers26A, the second deposition head 54A is inserted into the plurality oflayers 26A to inject lengths 46A of the second filament 56A into theplurality of layers 26A. The lengths 46A may extend from a top layer 48Ato at least two layers 50A, 52A below the top layer 48A. Once the driver42A has driven the heated needle 62A into the layers 26A, the extruderpushes the filament 56A through the second deposition head 54A thedriver 42A simultaneously lifts the needle 62A so that the length 46Aremains in the layers 26A. The length 46A may be injected substantiallyorthogonally to the layers 26A. However, the needle 62A may be insertedat alternative angles without departing from the scope of the presentinvention. Additionally or alternatively, the needle 62A may be used todisplace portions of the fiber 38A in the layers 48A, 50A, 52A so thatportions of the fiber 38A extend between two or more of the layers 48A,50A, 52A. Once the length 46A has been injected, the cutting device 64Amay cut the filament 56A at the top of the length 46A thereby depositingthe length 46A in the layers 26A. Alternatively, the lengths 46A may bedeposited into a plurality of layers 26A that are not at the top.Additionally, the lengths 46A may be cut prior to extrusion through theneedle 62A.

The flow chart of FIG. 4 depicts the steps of an exemplary method 100 ofadditive manufacturing a portion of the component 12. In somealternative implementations, the functions noted in the various blocksmay occur out of the order depicted in FIG. 4. For example, two blocksshown in succession in FIG. 4 may in fact be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder depending upon the functionality involved. In addition, some stepsmay be optional.

The method 100 is described below, for ease of reference, as beingexecuted by exemplary devices and components introduced with theembodiments illustrated in FIGS. 1 and 2. For example, the steps of themethod 100 may be performed by the deposition assemblies 20, 20A throughthe utilization of processors, transceivers, hardware, software,firmware, or combinations thereof. However, a person having ordinaryskill will appreciate that responsibility for all or some of suchactions may be distributed differently among such devices or othercomputing devices without departing from the spirit of the presentinvention. One or more computer-readable medium(s) may also be provided.The computer-readable medium(s) may include one or more executableprograms stored thereon, wherein the program(s) instruct one or moreprocessing elements to perform all or certain of the steps outlinedherein. The program(s) stored on the computer-readable medium(s) mayinstruct the processing element(s) to perform additional, fewer, oralternative actions, including those discussed elsewhere herein.

Referring to step 101, a plurality of layers 26 of filament 28 aredeposited via the FDM deposition head 22 to form the portion of thecomponent 12. The filament 28 may comprise the matrix material 36, suchas thermoplastic, and one or more reinforcement fiber 38. Thereinforcement fibers 38 may be coaxial with the filament 28 and comprisecarbon fiber.

Referring to step 102, an end 44 of an apparatus 24 may be inserted intothe layers 26 to displace at least one of the fibers 38 to result in adisplaced fiber 46. The end 44 of the apparatus 24 may be the point ofthe needle 40. The needle 40 may be driven into the layers 26 via theneedle driver 42 and removed via the driver 42. The driver 42 may insertthe needle 40 at an angle normal to the layers 26 and/or at differentangles relative to the layers 26. The needle 40 may be inserted so thatthe displaced fiber 46 has a portion that extends from a first layer 48to at least two layers 50, 52 below the first layer 48.

The method 100 may include additional, less, or alternate steps and/ordevice(s), including those discussed elsewhere herein. For example, themethod 100 may be repeated multiple times for each layer of filament 28deposited on top of the layers 26. Additionally, the method 100 mayinclude injecting lengths 46A of the second filament 56A into the layers26 via the second deposition head 22A.

The flow chart of FIG. 5 depicts the steps of another exemplary method200 of additive manufacturing a portion of the component 12. In somealternative implementations, the functions noted in the various blocksmay occur out of the order depicted in FIG. 5. For example, two blocksshown in succession in FIG. 5 may in fact be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder depending upon the functionality involved. In addition, some stepsmay be optional.

The method 200 is described below, for ease of reference, as beingexecuted by exemplary devices and components introduced with theembodiments illustrated in FIGS. 1 and 2. For example, the steps of themethod 200 may be performed by the deposition assemblies 20, 20A throughthe utilization of processors, transceivers, hardware, software,firmware, or combinations thereof. However, a person having ordinaryskill will appreciate that responsibility for all or some of suchactions may be distributed differently among such devices or othercomputing devices without departing from the spirit of the presentinvention. One or more computer-readable medium(s) may also be provided.The computer-readable medium(s) may include one or more executableprograms stored thereon, wherein the program(s) instruct one or moreprocessing elements to perform all or certain of the steps outlinedherein. The program(s) stored on the computer-readable medium(s) mayinstruct the processing element(s) to perform additional, fewer, oralternative actions, including those discussed elsewhere herein.

Referring to step 201, a plurality of layers 26A of filament 28A aredeposited via the first FDM deposition head 22A to form the portion ofthe component. The filament 28A may comprise the matrix material 36A,such as thermoplastic, and a reinforcement fiber 38A. The reinforcementfiber 38A may be coaxial with the filament 28A and comprise carbonfiber.

Referring to step 202, a needle 62A of a second deposition head 54A maybe inserted into the layers 26A. The needle 62A may be driven into thelayers 26A via the needle driver 42A. The driver 42 may insert theneedle 62A at an angle normal to the layers 26 and/or at differentangles relative to the layers 26A. The needle 62A may be inserted intoat least the three topmost layers 48, 50, 52 of the plurality of layers26.

Referring to step 203, the length 46A of the second filament 56A may bedeposited in the layers 26A via the needle 62A of the second depositionhead 54A. The second filament 56A comprises the matrix material 66A,which may comprise thermoplastic, and the reinforcement fiber 68A, whichmay comprise carbon fiber. The reinforcement fiber 68A may comprise acontinuous fiber that is coaxial with the second filament 56A. Thelength 46A may be deposited so that it extends into the next layer orpreferably between at least three layers 48A, 50A, 52A. The three layers48A, 50A, 52A may be the top three layers. This step 203 may includeremoving the needle 62A via the driver 42 while the extrudersimultaneously pushes the second filament 56A through the seconddeposition head 54A so that the length 46A replaces the hole formed bythe needle 62A. Additionally, the length 46A may be cut from the secondfilament 56A via the cutting device 64A.

The method 200 may include additional, less, or alternate steps and/ordevice(s), including those discussed elsewhere herein. For example, themethod 200 may be repeated multiple times for each layer of filament 28Aapplied on top of the layers 26A. Additionally, the method 200 mayinclude displacing lengths of the fiber 38A in the layers 26A via theneedle apparatus 24 and/or second deposition head 54A.

Although the invention has been described with reference to theembodiments illustrated in the attached drawing figures, it is notedthat equivalents may be employed and substitutions made herein withoutdeparting from the scope of the invention as recited in the claims.

Having thus described various embodiments of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:
 1. An additive manufacturing assembly comprising: a firstfused-deposition manufacturing deposition head configured to deposit aplurality of layers of a filament comprising a reinforcement fiber andthermoplastic material; and an apparatus configured to causereinforcement fiber to extend to at least three layers of the pluralityof layers.
 2. The additive manufacturing assembly of claim 1, whereinthe apparatus comprises a needle apparatus configured to be insertedinto the plurality of layers to displace the reinforcement fiber fromthe first fused-deposition manufacturing deposition head so thatdisplaced fiber extends the at least three layers of the plurality oflayers.
 3. The additive manufacturing assembly of claim 2, wherein theneedle apparatus comprises a needle and a needle driver configured tocause the needle to reciprocate in the plurality of layers.
 4. Theadditive manufacturing assembly of claim 3, wherein the needle driver isconfigured to reciprocate the needle vertically into the plurality oflayers.
 5. The additive manufacturing assembly of claim 2, wherein thereinforcement fiber comprises at least one of carbon fiber, glass fiber,basalt fiber, ceramic fiber, metal fiber, aramid fiber, polyesterfibers, natural fibers, or metallized fibers.
 6. The additivemanufacturing assembly of claim 1, wherein the filament deposited by thefirst fused-deposition manufacturing deposition head is a firstfilament, and the apparatus comprises a second fused-depositionmanufacturing deposition head having a needle tip configured to beinserted into the plurality of layers to inject a length of a secondfilament comprising thermoplastic material and a reinforcement fiber sothat the reinforcement fiber of the second filament extends along the atleast three layers of the plurality of layers.
 7. The additivemanufacturing assembly of claim 6, wherein the reinforcement fiber ofthe second filament comprises a continuous fiber, further comprising acutting device configured to cut the continuous fiber.
 8. The additivemanufacturing assembly of claim 6, wherein the length of the secondfilament is orthogonal to the reinforcement fiber in the plurality oflayers of the first filament.
 9. The additive manufacturing assembly ofclaim 6, wherein the first fused-deposition manufacturing depositionhead and the second fused-deposition manufacturing deposition head arecoupled and move horizontally together above the plurality of layers.10. The additive manufacturing assembly of claim 6, wherein the secondfused-deposition manufacturing deposition head comprises a heater blockconfigured to heat the needle tip.
 11. The additive manufacturingassembly of claim 6, wherein the needle tip is configured to displacethe reinforcement fiber of the first filament.
 12. An additivemanufacturing assembly comprising: a first fused-depositionmanufacturing deposition head configured to deposit a plurality oflayers of a filament comprising a reinforcement fiber and thermoplasticmaterial; and a needle point configured to be inserted into theplurality of layers to displace the reinforcement fiber so that itextends at least three layers of the plurality of layers.
 13. Theassembly of claim 12, wherein the reinforcement fiber is coaxial withthe filament.
 14. The assembly of claim 12, wherein the filamentcomprises a plurality of reinforcement fibers.
 15. The assembly of claim12, wherein the reinforcement fiber comprises at least one of carbonfiber, glass fiber, basalt fiber, ceramic fiber, metal fiber, aramidfiber, polyester fibers, natural fibers, or metallized fibers.
 16. Anadditive manufacturing assembly comprising: a first fused-depositionmanufacturing deposition head configured to deposit a plurality oflayers of a first filament comprising a reinforcement fiber andthermoplastic material; and a second fused-deposition manufacturingdeposition head having a needle tip configured to be inserted into theplurality of layers to inject a length of a second filament comprisingthermoplastic material and a reinforcement fiber so that thereinforcement fiber of the second filament extends two or more layers ofthe plurality of layers of the first filament.
 17. The assembly of claim16, wherein the fiber of the second filament comprises a continuousfiber, further comprising a cutting device configured to cut thecontinuous fiber.
 18. The assembly of claim 16, wherein the length ofthe second filament is orthogonal to the reinforcement fiber in theplurality of layers of the first filament.
 19. The assembly of claim 16,wherein the reinforcement fiber of the first filament and thereinforcement fiber of the second filament comprise at least one ofcarbon fiber, glass fiber, basalt fiber, ceramic fiber, metal fiber,aramid fiber, polyester fibers, natural fibers, or metallized fibers.20. The assembly of claim 16, wherein the first fused-depositionmanufacturing deposition head and the second fused-depositionmanufacturing deposition head are coupled and move horizontally togetherabove the plurality of layers.